I've looked high and low and cannot find an answer to this question.
Lets say I have a custom object called Appointment__c which is a child of the Case object, I have a VisualForce page that is launched on the Appointment level. At the moment, the visual force page retrieves the Appointment Id and retrieves case Info. I have a separate query that retrieves the appointments using the case Id. My question is, is there any way to retrieve the case's appointments using only the original appointment Id?
For example, if I have Case 1 with Appointment A, B, C and the VisualForce page controller is instantiated with Appt A, is there any way to directly retrieve A, B, and C from A in one query without first having to query for Case 1's ID and then using another query to retrieve Appointments for case 1?